Freight Cost - Item Cat determination in VI01 T.code

Hi Gurus,

In transporation module, shipment cost creation, in VI01, item cat will coming automatically Z001, i need to get Z006, its in non modifiable mode, where we can do configaration in TM, if any notes on Transporation module configaration please forward the same to - ramakrishna.pullikanti at the rate gmail dot com.